A cleaner way to convert a function declaration into a function expression would be to use brackets<p><pre><code> (function() {
//code here
})();
</code></pre>
This won't affect the return type of the statement; which in case of using ! will return boolean 'true' unless the function returns a truthy value. Plus using ! for this purpose, looks totally messy.
FYI, the blog post suggests that bootstrap is currently developped at twitter, which is not the case anymore @see <a href="http://getbootstrap.com/about/" rel="nofollow">http://getbootstrap.com/about/</a>